DE 42 23 296 C2 proposes a drive system for four wheel drive vehicles. An internal combustion engine with a gearbox, via a first driveline, directly drives a first driving axle. A second driveline comprises a superposition drive with two inputs and one output which serves to drive the second driving axle of the motor vehicle. The first input is driven by the output shaft of the gearbox with a constant transmission ratio. The second input of the superposition drive is driven by an infinitely variable traction mechanism drive with a variable rotational speed. There thus exists a driving connection between the traction mechanism drive and the output shaft of the gearbox. Separating the superposition drive from the gearbox in terms of location is not possible.